In Variable Speed Pumping systems the chiller must be protected from changes in flow rate because changing flow rates can cause pressure fluctuations in the refrigerant. This can lead to discharge of refrigerant and the resulting environmental damage to the space. Traditional installations use a modulating control valve at the chiller to try and maintain a constant flow, or at least a flow above the minimum allowable flow.
The Griswold Controls’ MVP® not only maintains a constant flow regardless pressure changes – but it also has a position display on the actuator. That means you can tell what position the actuator is in at any time.
Using the chart provided with the valve you can cross reference the actuator position to the actual flow rate so you know the flow rate at any given moment. The actuator can also provide feedback to the control system so that the control system knows valve position and therefore flow through the chiller to make sure it does not drop too low. The MVP® valve is a small price to pay to protect such an expensive piece of equipment like a chiller.
Do you have a question on this Application Tip or any of the Griswold Controls products? Fill out the form below and someone from Griswold Controls will get back to you shortly.